Thursday, August 2, 2007

Mitral Valve Replacement (MVR)

Finally, I convinced myself to watch at least one open heart surgery. I was surprised at how invasive the whole procedure was. The doctors’ basically sedated the patient, sliced his chest open, and then pulled his ribs apart using their bare hands or a crude mechanical device. It was almost like watching a scene out of a movie with hygienic zombies in scrubs trying to carefully eat the victim’s heart. Okay, maybe that’s an exaggeration. What followed was a bit more impressive. They bypassed the patient’s arteries, immobilized the heart using high concentration of potassium chloride, and then made an incision in the heart in order to replace the mitral valve. The following picture is borrowed from It depicts a mitral valve replacement.Apparently, this particular patient had mitral valve regurgitation. This was evident from his transesophogeal echocardiogram or the ultrasound measurements. One could see that the oxygenated blood that entered the left ventricle through the mitral valve periodically reentered the left atrium. In most cases, a patient’s valve is irreversibly compromised due to either ischemia, stenosis, or infection. These problems are usually onset due to coronary artery disease, age, or rheumatic fever, respectively. However, congenital defects are not rare.

In the patient’s case, the problem was caused by ischemia through coronary artery disease. As a result, the doctor had decided to replace his valve with a bovine valve - the reasons for choosing a bovine valve or a mechanical valve were explained previously by Dickinson. It seemed as though the stitching of the valve required great dexterity. One of the more skilled residents tried to stitch the valve but it seemed as though he could not make the more difficult 10-12 o’clock stitches. As a result, the primary surgeon took over and showed him how it should be done.

One could definitely make it easier for these doctors by developing an innovative device for sewing. In fact, I don’t really know why a big hospital like NYP still uses open heart surgery for such cases. There are hospitals that are performing these types of procedures percutaneously using the da Vinci surgical system. I think that’s the way to go. If not, the least one should do is make something that replaces the “needle and string.”

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